VALONIACEAE. 495 



submerged rocks and logs. (Phyc. Bor.-Am. 1867 ; Alg. Exs. Am. Bor. 171, 

 as V. utricularis Ag.) 



Ernodesmis verticillata (Kiitz.) B0rg. This plant was formerly consid- 

 ered to be a Vcdonia, to which genus it is closely related. The plant is 

 repeatedly branched, the slender club-shaped branches or vesicles occurring 

 in whorls of 4 to 12. The species has been found in Harrington Sound and in 

 a shallow tidal stream flowing into Hungry Bay. (Phyc. Bor.-Am. 1907.) 



Dictyosphaeria favulosa (Ag.) Decaisne, has been found at Harris Bay 

 by Hervey (Phye. Bor.-Am. 2015). It forms hollow membranous thalli that 

 are at first subglobose or lightly wrinkled or lobed, becoming later irregularly 

 torn or somewhat cup-shaped, the thallus often as large as one's fist. The 

 surface of the thallus shows numerous hexagonal facets, mostly a half line or 

 less in diameter, suggesting a miniature honeycomb. The plant grows at- 

 tached to rocks in shallow water. 



Siphonocladus tropicus (Crouan) J. Ag. has lateral flagelliform branches 

 0.5-2 inches long, clothed with irregular often crowded proliferations mostly 

 r ^-i inches long. 



Siphonocladus rigidus M. A. Howe, has, for the most part, a dichotomous 

 or subdichotomous mode of branching, though short, irregular or subsecund, 

 mostly unicellular, lateral proliferations are of occasional occurrence. The 

 cell walls are thick and under a microscope conspicuously lamellate, and the 

 septa are often mammillate or tuberculate on their upper faces. It grows on 

 rocks and pebbles in shallow water or at the low-tide line. Agar's Island 

 (Collins). (Phyc. Bor.-Am. 2169.) 



Petrosiphon adhaerens M. A. Howe, forms closely appressed slightly calci- 

 fied light green crusts or cushions in tide-pools or on limestone rocks near the 

 low-water mark. It has a radially striate or suleate appearance owing to its 

 radio-marginal growth. The plant is actually attached to the rock by boring 

 rhizoids and can not well be removed without use of hammer and chisel. The 

 species was originally described from the Bahamas, but has recently been 

 found in the Bermudas by Hervey. (Phyc. Bor.-Am. 2073.) 



Anadyomene stellata (Wulf.) Ag. is not uncommon on rocks, growing 

 mostly in 1-20 feet of water. It forms a membranous bright green subsessile 

 thallus usually 1-3 inches high or broad and looking a little like a young r/ra 

 but crisper and more rigid to the touch. Under a hand-lens or even to the 

 naked eye it shows an elegant system of venation, with the principal veins 

 radiating in a palmate, flabellate, or semicircular fashion from radially suc- 

 cessive foci. (Phyc. Bor.-Am. 1906.) 



Struvea ramosa Dickie, was originally described from the Bermudas from 

 material dredged in deep water by the Challenger Expedition and has since 

 been reported from the Canary Islands. The plant is two or three inches tall, 

 more than half of which consists of the slender simple or oppositely branched 

 stipe, which is rugose-annulate near the base or also at the base of its branches. 



